#!/usr/bin/env python3
"""
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""

"""
The C extension loader for various platforms.

NOTE: this module should be on top level

Example of usage:

def _import_c_scanstring():
    from . import c_extension
    _speedups = c_extension.get()

    if _speedups:
        try:
            return _speedups.scanstring     #  import here required functions
        except AttributeError:
            pass

    return None
"""


def get():
  _path = ".".join(__name__.split(".")[:-1])
  # trying to load extension from available platforms
  _import_paths = ["_speedups.posix.usc2", "_speedups.posix.usc4", "_speedups.ppc", "_speedups.win"]

  for _import_path in _import_paths:
    try:
      return __import__("{}.{}".format(_path, _import_path), fromlist=["_speedups"])._speedups
    except (ImportError, AttributeError):
      pass

  return None


def is_loaded():
  """
  :rtype bool
  """
  return get() is not None
